Transfer mechanism



Oct. 9, 1951 H. F. PHILLIPS TRANSFER MECHANISM 8 Sheets-Sheet l FiledMarch 20, 1947 Oct. 9, 1951 HfF. PHILLIPS 2,570,589

TRANSFER MEcHANrsM Filed March 20, 1947 8 Sheets-Sheet 2 INVEN TOR.#f1/PRY f Pff/UPS -----IITV |||||.\H a l lllTml Oct. 9, 1951 H. F.PHILLIPS 2,570,589v

TRANSFER MECHANISM Filed Maron 2o,- 1947 a sheets-sheet s Ti Z.

/9 7' TUF/VE Y 181 'Sheets-Sheet 4 H. F. PHILLYIPS TRANSFER MECHANISMOct. 9, 1951 Filed March 20, 1947 Oct. 9, 1951 H. F. PHILLIPS TRANSFERMECHANISM 8 Sheets-Sheet 5 Filed March 2O, 194'? Oct 9, 1951 H F.PHILLIPS 2,570,589

TRANSFER MECHANISM Filed March 20, 1 947 8 Sheets-Sheet 6 INVENToR.,fm/PPV f P/f/L/P BY @w71 Oct. 9, 1951 H. F. PHILLIPS TRANSFER MECHANISMFiled March 20, 1947 8 Sheets-Sheet 7 INVENToR. HAPPY PH/L/Ps O Ct 9,1951 H. F. PHILLIPS 2,570,589

, TRANSFER MECHANISM Filed March 20, 1947 8 Sheets-Sheet 8 Byvzm vINVENTOR. JCI-l- #4f/PPV F Pff/MP5 Patented Oct. 9, 1951 TRANSFERMECHANISM Harry F. Phillips, Springfield,"Ma'ss., assigner to BauschMachine Tool Company, Springfield, Mass., a corporation of MassachusettsY Application March 20, 1947, Serial No. '736,034

My'present invention relates to almechanism whereby work pieces to'bemachined may be transferred in ordered sequence through one or morestations relative to machines and may be accurately positioned at eachstation.

In the mechanism of my invention Work pieces are successively placed instarting position by an operator and are then transferred from oneposition or station to the next without further intervention by theoperator except to start or stop the mechanism or the machinesassociated with it. Any number of mechanisms and their associatedmachines may be arranged in sequence and the work pieces are thentransferred automatically from one mechanism to a succeeding one.

Each transfer mechanism is under the control of the machine associatedwith it so that a Working station it is'located accurately by locatingdevices, such as hydraulically actuated pins, Which move into accuratelypositioned openings or holes in the Work piece when it is in correctposition. When the Work piece is located in a station by the locatingpins it is clamped securely work piece is not moved to the workingstation Y until the machine, such as a drilling machine, is ready tostart the machining operation at that station and is not moved to thenext succeeding station until the machine has completed its operationand is ready to receive a succeeding piece. When transfer mechanisms arearranged in sequence, the starting or loading station of one mechanismmust be vacant before the preceding mechanism is set in operation todeliver a work piece.

It will be apparent, therefore, that no work piece can be moved into astation until the machine is ready yto receive it and until themachining operation on a preceding work piece has been completed. Thesuccessive mechanisms are thereby timed to the slowest machine althougheach mechanism may itself vbe otherwise independent.

Inasmuch as each transfer mechanism is a complete and separate entity,any number of mechanisms may be combined with a corresponding number ofmachinesto accomplish any desired number of machining operations and maybe readily changed about or adapted to changes in the order or types ofmachines and machining boring machine, planer or Shaper or profiler,orga4 machine for turning the work piece to a different position for asucceeding operation, or it' may be apparatus for inspecting the workaccomplished in preceding machines.

in position by hydraulically actuated bushing or clamping'plates whichhold it throughout the machining operation.

The transfer element may carry a transfer pin, or similar mechanism,Which is depressed when the clamping or bushing plate is depressed andwhich may, therefore, move underneath the path of the Work piece whenthe transfer bar moves reversely and to engage a work piece and move itfrom one station to the next when the clamping plate or element isreleased.

These various mechanisms are preferably controlled by valves so arrangedthat each element may move only in its proper sequence and timing. Thus,the valves are so arranged that the clamping plate is lowered intoclamping position only when the locating pins or elements have movedl tolocating position. The transfer element moves y reaches its rearmost orstarting position it then operates a control valve to cause theclampingl plate and the transfer pin to rise and the locating pin to beretracted, whereupon the transfer bar Ymoves forwardly carrying with itthe work piece f 'clamping plate to clamp the work piece in its trolswitches at the loading stations of the mechlocated position.

These hydraulically operated valve mechanisms insure that each of thesemovements Will take place in its proper sequence and only when the'preceding operation has been successfully and fully completed, I

These hydraulic mechanisms are in turn elec-v trically controlledjointly by the machine associated'with the transfer mechanism and byconanism and the one next succeeding. This control circuit releases thehydraulic mechanism to advance a work piece when the machine hascompleted its' operation and Withdrawn, when the loading station isloaded and that of the next succeeding machine is empty. It alsocomprises a starting switch for the machine actuated by the clamping ofthe clamping mechanism and a switch actuated by the withdrawal of thelocating pins to permit forward movement of the transfer element. l

The various features of the invention are illustrated, by way ofexample, in the accompanying drawings in which- Fig. 1 is a side View ofa transfer mechanism embodying a preferred form of the invention, partsbeing broken away to more clearly show the construction; I

Fig. 2 is a plan view, and Fig. 3 is an end view of the mechanism shownin Fig. l; n i

Fig. 4 is a transverse sectionona largerscale on line 6 4 of Fig. 2,showing the transmission mechanism for the transfer bar and pin;

jFig. v is a horizontal section takenon line 5 -5 offFigjB, showingtransmission 'ele'rlientsl for "the clamping plate, 'tfansjfeibrandlatifigps Fig. 7 isa verticalsect'ion'takn'fromftne right ofwFig. 5'ofu a hydraiilic cfylinder and a lpa'tfofa transfer forthe transferbar;A

Fig. 8'is aodetail ofY the 'transferbr and trans'- m'isiciis..

Fig.v '9 `a Aside nview \of` a Voer'tziin valve control mechanism; y d nn Fig. lqis a diagrammatic 'outli'f' fof tliehydraulic controluvalvesand connections;

Fig. Y 12 Vis a'wiringdiagram showingtlie' controls for the hydraulicvalve control system shown in Fig. 10.

Referring toA the Yenb dment 'the vinvention Shcwii iiiihccccciiipeiiyiis die iiigs. c wcik piace iiiicccciic. thestcriiriaiicsiticcc icfiiccicc ci .1..5-Fic- 1, @gemir .ciScpccriiiicrcilc..iciid Il ities.- .lcnd ii. which. csiciid .tricv i.cil.iccg'ih ci the. ,machine-...T csc rails crccccpcricc. cnc ircirici4Wiiiciii i in is ciciiiitccciigcccbiiii [9l Figslfandgjw ich may containallor partY The Work 'piece ,ic mcvciiircm the.. iiqsiiicii shcirn ai.I5 .Successi/cls'-tty ,sicticiic indicated@ @and 2i, twostiicns @eineshcwiiby ci cianplc, and tiicnccic c .Startins Sicticc Qc c Succeedingmachin? .2.3` br .means cf c Suitable transfer` mcchcnism .which mcrcsc.Slisics. .the Work piece on the rails I6 and l1 fromv one stationicihcncxt- ...The vwcrk pieces. crc guided against ,Sidcwiccdisplacement in moving over thesupportingwrails I6 and 1 by means ofguide rails 24 and 2 5 mounted above the rails I6 and 1 1 by' r n`eansof scitcblelcrcckccc and. 2.1. .'ilicisiiidc icilcmcy bvelged@ ih?Qntlalends! dfatqt 28.1ar1d 29, in cider icrcccivc cwcrk piece cvnthcugh it may ,bc ciiicwhac Gignac@ It will be understood that thegiiide'railsugd ccc-.c2c ,iiccd' cci iccA ,ccctiiicccs ihic shccc -ih'c lengthcf che machin@ bctiiicrlccciadc. iii'cc.- tions and also secured4otherwise than by the brackets 26 and 2'l.

Transfer 'bar'undfp'in 32 extending from the supporting rails I6 and l1.These anges support the transfer bar 30 and enable it to slidelongitudinally between the rails i6 and Il' for a limited distance equalto the distance between the respective stations I5 and 2l and 26 and 2|.In the advance position of the transfer bar it extends from its rearend, shown at 3 3 in Fig. 2, to* the opposite endfofthe supporting railsI6 and l1. When in reverse position vthe end 33 would be at the front orstarting end 'of the rails I6 and l1.

Thetra'n'sfer bar is driven alternately in forward and reversedirections by means of a hy- Yd1"afilic'ally operated piston 34 in acylinder 35 attachedtothesiderof the frame i8, Figs. 2, 3 and li. Y Thepiston is provided with a stem 36 extending ifin'tda yVc'a'sing 31having an adjusting screwjt at its end to adjust the limit of movementof the piston and stem.

rfhepiston stem S6 is provided with rack teeth 3,9'y which fmeshwithjpinion 4teeth `l46 --on a cross shaft l, Figs. 13 and 4;*extedng'into the fra-nie le and tematica-therein :ma bearing'fefz. fiche Ysh'jftll may alsobejjcurnalled in ah'alf bearing i3 in the casingS. Asthe piston *36 andis'ter'n3'6 reciprocate they vgive Aalternatelyreversed V'rotations to 'thei'shaftL i Arme opposite endof mechant-is-securdija pirfionil which "meshes with iarra'ckfi 'secured to "the'undersnrface of lthe 'transferbar S'so 'that the reciprocatingmovements 'of the pistons-34 are 'transferred throug'hthegshaft fil-I torecipr`o`' eating vlon'gitiidinal Amovements wof lthe transfer bar an.

1t willbe "understood, as indicated vby the different diameters of thepinions 46 A"andtl,jtl'iat the movement of I'th'epistcin''may be shorterthan that of the transfer 'barl or 'may beincany relative proportiontlii't. Thlllh tldalt'elate'- ciprocations ofthe pston'in the cylinder35, the transfer '-bar V`is moved forward `to thepdsitin shown l2,or`r`versely,' to a'startingfpo'si'- tion at the starting or'frontendnof' the 'machine Y @hev transfer bar isbelow'the level'ofth'e n'lrsurfaces of the railslBland"lfandftherefore, t of contact with thejworkpiecesfthereon. 'Ic engage and carry forwardthe workpieces'with eachforward movement-ofthetransfer bar vertioal'slidable transfercpins `46,41 and 48 are provided, there-being one for each 4of the stations I5,2i! and'Zl. -The transferpins 46 andyll'lare spaced va distanceegual tothe distance between thestations l'and 2Q or20 and2|. AThe transiferipin dais; providedf'at its-upper -end with-abifurcated horizontalextension 49, the frontend of whichis'distant =from'the vpini-i8 byI a`distance equal t'o the distancelbetweenvthe separate "stations, f this'distanceY being sufficient f to i cause this extension toproject"over-"the=` 'endof the machine andfto'v the starting position'"of thefnextv machine.

Vifh'e extension piece 4:9 being f'bfurcated provides iai slot "toreceive ffa'v transfer Vpin-'56 4'of j-the succeeding machine 2,3 sothat the worki'pie'ce may i bel picked! 'upf-byftl'iefltra'nsfermechanism of the succeeding machine.

downwardly acting clamping mechanisms Wh-ich.

Clamping mechanism The clamping mechanism of the stations 20 and 2|respectively comprises vertically movingv clamping plates y5| and 52,the construction and operating mechanisms of which are substantiallyidentical.

`Referring more particularly to the clamping mechanism of station 28,the clamping plate 5| is supported by a pair of vertically movable rodsor shafts 53 and 54 at diagonally opposite positions of the plate 5Iwhich slide in suitable guiding grooves in a supporting frame 55.Y Theup- Ward movement for unclamping the plate 5| and the downward movementfor clamping it are imparted to the lower ends of the supporting andoperating rods 53 and 54 by means of a reversely driven shaft 56extending transversely of the machine below and secured to the frame I8,as shown in Fig. 6, and provided with gear teeth 51 and 58 at itsopposite ends that mesh with rack teeth 59 and 60 on the lower ends ofthe shafts 53 and 54.

The lower ends of the vertical movable rods 53 and 54 extend through orinto housings 6I and 62 which are secured to the lower surface of theframe I8 and also carry the ends of the shaft 56 and the gear teeththereon. Through the crossshaft 56, therefore, both of the rods 53 and54 are moved simultaneously and for the same dista'nce with each rockingof the shaft 56.

A rocking movement is imparted to the shaft 56 by means of ahydraulically operated piston 63 in a cylinder 64 to the piston stem ofwhich is attached a rack 65 meshing with suitable gear teeth 66 in themid part of the shaft 56. In this way the vertical movement of thehydraulic piston 63 is imparted equally to the lifting rods 53 and 54and uniformly to the clamping plate 5| or 52 respectively, it beingunderstood that each clamping mechanism has its own individual operatingpiston and transmission mechanism.

Also secured to the clamping plate 5| is a pair ofvertical slide rods 61and 68, Figs. 1 vand 2,V which extend downwardly into the frame I8 tothe position shown in Figs. 1, 3 and 4. These rods 61 and 68 beingsecured to the plate 5I move upwardly and downwardly with it, beingguided by suitable guides 68 in the framework 55.

The rods 61 and 68 extend below the rails I6 and I1, as shown in Fig, 1,and have clamped Vat their lower ends brackets 18 and 1I which serve toraise and lower the transfer pins 46, 41 and 48 through a suitabletransmission mechanism.

As shown more particularly in Figs.3 andv 4 the brackets 18, 1| carry avertically movable grooved guiding bar 12 which extends below thetransfer bar 38 a distance at least equal to the distance between thetwo stations.

.At the lower end of the transfer pin 48 is mounted a roller 13, Figs. 3and 4, which extends into the groove 14 of the bar .12 so that as thebar 12 is raised and lowered by the bracket 1 10, rod 6I and clampingplate 5I, the transfer pin 46 will be raised andl loweredaccordingly, atthe same time the transfer pin 46 may move with the transfer bar vSII,longitudinally of the lifting guide 12, the roller 13 moving 1ongitudi`nally in the groove 14. In this way the pin 46 is caused to moveupwardly when theclamping..

plate is raised and downwardly when the clamping plate is lowered inclamping position.

The upward and downward movementof theY pin 46 is transferredsimultaneously to the pins Y 5 f; 41 and 48 by means of a shaft 15,Figs. 2, 3 and 4,' carried in the transfer bar 38 and extendinglongitudinally thereof and having gear teeth that mesh with rack teeth16 on each of the respective transfer pins so that all rise and lowersimultaneously and equally.

It will be apparent, therefore, that the clamping plates control thetransfer pins, that the transfer pins are lowered and may be movedreversely to starting position when the clamping 15. plates are downholding the respective work pieces, and that the transfer pins rise toengage their respective work pieces and move them' forwardly only whenthe clamping plates or bushing plates are lifted or unclamped.

# Locating mechanism When a work piece is moved into the station 28 or2| it is accurately located in positionbe- 1 fore being clamped so thatit may be in exact position for the machining operation at that station.For this purpose the work piece isprovided with locating openings,preferably two, which are engaged by locating pins 11 and 18, one foreach station, and positioned to move upwardly and' 3o .lit closely intothe locating openings of the work piece when the latter has been broughtinto the respective station by the transfer bar and pins.y Preferablythe upper ends of the locating pins 11 and 18 are rounded or pointed sothat they will nd the locating openings of the work pieceA if the latteris slightly displaced from the proper position and will thereby move itinto the exact position it is to occupy for machining.

The locating pins are raised and lowered through a suitable transmissionmechanism by means of a hydraulically operated piston 19 in a cylinder80 mounted on the lower face of the frame I8 as indicated in Fig. 7. Thepiston 19 is provided with a stem 8| having rack teeth that mesh withsuitable gear teeth on a shaft' 82 extending longitudinally of themachine below the respective stations 20 and 2|.

The shaft 82 is provided with gear teeth 83- and 84 respectively thatmesh with corresponding rack teeth in the locating pins 11 of therespective stations 28 and 2|, causing the pins 11 to lower when thepiston 19 is raised and, reversely, to raise the locating pins when thepiston 19 is lowered, the piston rod 8| being on the opposite side ofthe shaft from the locating pins 11.

The rocking movement of the shaft 82 is transferred to a second shaft 85parallel to the shaft 82 by4 means of a transverse rack bar 86, Figs. 5

and 1l, sliding in a housing 81 on the undersurface of the frame I8 andhaving rack teethA that mesh with gear teeth 88 and 89 respec-v tivelyon the shafts 82 and 85.

Through the rack bar 86 the movements o the shaft 82 are transferred tothe shaft 85.

These movements are in turn transferred from the shaft 85 to thelocating pins 18 by suitable gear teeth that mesh with rack teeth inthepins 18 so that the pins 18 of both of the stations move simultaneouslywith the pins 11. In theY g event that the pins 11 and 18 cannot riseinto the locating openings in the work piece, either due to displacementof the work piece or other causes, the'pressure on the upper vside ofthe piston 19 will be insufficient and the piston will 75,*notbe ableYto drop and lower the piston rod 8Il.'J

. Hydraulic 'control :mechanism The'transfer elements, the clampingelements and the locating mechanisms'are loperated'in relative sequenceby an V'interlocking hydraulic system. A

vThe system so controls Vthe admission offluid to the cylinders 35, 84and 80 'that veachofl the elements operates in its appropriate relationto theo'thers. Thus, before the transferpin can move to startingposition 'the clamping Aplates mustbe lowered, and 'with themthe'transfer pins, so that each work piece'in any jworking station isheld securely while the transfer'pin is free to-move reversely. Theparts remain 'in these positions Vuntil vthe 'transfer bar has completedits rearward movement, thereupon theA locating pins are withdrawn and intimed 'relation thereto the clamping plates are lifted orunclampedraising the transfer pins.

When these operations have been completed iluid vis admitted to thecylinderr35 in such a manner as to cause the transfer barand transferpins to advance moving each work piece to the .next `succeeding station.'The locating pins thereupon rise to locate the work pieces accurately.

'If' for any reason 'the locating pins fail to rise, the clamping platescannot be lowered and no further operation can take place. If the pinsdo rise, properlyA locating the work piece, the clamping` plates loweralso lowering the transfer pins and remain lowered until the machiningoperation is completed, thereupon the cycle of operation is repeated.

"The fluid under pressure for operating the hydraulic mechanisms andvfor operating the various fluid control elements is drawn from a supplytank, indicated at', by means of a pump 9| driven by a motor 92 andsupplied to a supply main 93. The pressure in the supply main 93 islimited byineans of a relief valve 94 which opens upon generation ofpressureabove a predetermined limit to admit fluid from the main 93through a return circuit 95leading back to the supply tank 90.

The main 83 leads to a distributing valve SB controlled alternatively bya pair of electro-magnets 91, 98. The electro-magnet or solenoid 91 isenergized by an electrical system when the station 22 of the nextsucceeding machine is .empty and the station at I is lled, when thebush-ing plates are clamped, when the locater pins are raised andwhenth'e rear limit Vswitch of the machine tool mechanism is in its backor withdrawn` position.

When the solenoid 91 is energized the valve 9S opens communication from.pipe 93 through a branch pipe 99 to a distributing pipe |08, Aall ofthese pipes being of relatively large ksize as, .for example, indiameter, through which .fluid is supplied through timing valves to thecylinders 35, 64Iand 8G.

Fluid. is also suppliedthrough asmaller control line *IUI to a pair ofkcontrol valves |82 and `I|3 which are alternately opened and closed bymechanism connected to the clamping plates 5| and 52, the valve |82being open when the Aclamping plate is down and closed whenthe clamping'plate is up, and the valve |83, reversely, beingclosed when theclampingplates are down landf'open when they are up. Y

As shown in Figs. l, 5 and `9, the rod51 of.rthe. clamping :plate is`extended. throug'hfthe :base of "the, frame' I8 zand into the.cabinet-CIS being...

guided in,.a1suitable .guide boX IM,l secured to the underfaceof thebaseroftheframe I8. VTherod 81Jis positioned vaboverthe valve |82 andhas an extension :.I051to x .contact withthe stem of .the yvalve |82,

ftocontactwiththestem of the valve |83.

Throughthe abovemeehanism the valves|02 and |83 are controlled andoperated in opposite directions from the clamping plate 5|. Whentheclamping. plate-is!dow-nv the valve |92 ismoved .in

such a "-directiontasfto permitthe passage of .pressure fluidV fromthe1line|| .to a control line V|139 leading .to the lower end of a valveil and acting toopen lthis Valve. Y

The-.solenoid91 .being activated the pressure fluid flows-from thezpipe9.9 into .a-pipe I -leading to the valve |10 and through `'this valvethroug'hline I |2 and forwardly through a check valve I |3 and line H8to the left hand side of the cylinder-35, the cylinder `is therebyforced 4right and, reVerSely, Ycarries the .transfer bar 35 to star-tingI position.

The movements Yof the transfer bar 38 -are transmitted to the hydrauliccontrol system-by means of a suitable mechanism which comprises :a bevelgear'I |5,1Figs. 1 and Y4, xed on andv ro-Y tating with the shaft*C12-and meshing with a bevel gear IIS xed ona vertical` shaft I|1 whicheX- tends below the base of the frame I8, as shown in Figs. 1 and -5.The rotation in either direction of the shaft ||1 is `transmitted vbymeans of bevel gears IIS and IIB to a horizontal shaft |28 and lthencethrough bevel'gears |2|, |22, to a shaft On the front end of the shaft|23 is a pinion |24, Fig. 7., .which meshes with a gear '|25 on a' shaft|28 which also carries va control disc |21. Mounted on the disc `|21.area pair of adjustable cams |28 Vand |29 which, as the disc |21 rotatesthroughout somewhat lessthan a full revolution, contact alternatively,and open, .hydraulic valves |38 and |3| respectively,"Fig. 9.

The mechanism is so arranged that when .the transfer bar moves inreverse directionto the startingY position the valve |30 will be openedand valve |3i closed at the end of vthe stroke, and when it movesforwardly to theend Aof its forward stroke valve I.3| will be opened andValve |30 closed.

When the valve I3v8is open pressure fluid flows from the line|| througha branch lead line |32 throughrthe valve |35 ,and thence to line |33'through a control valve |34, opening this valve. Fluid then `flows fromthe line Iii through fa branch line |35 and'through the open valve |34and line |36 to the lower ends of clamping cylinders 54 'raisingthesecylinders and unclamping thek clamps and alsoflifting the transferbar pins. The lifting of therbushingwclamps Vserves `te reverse the'valves "|82 Iand |83, through the mechanism described above, openingva'lve'i'i and closing .valve 182. Fluid thereupon flows from 'the lineIBI througha loranchline |31 and thence through the `open valve |03 toline |38 into the' bottom. of a control valve |39 vand opening thisvalve. :the `valve. is opened `fluid flows Vfrom the branch II35"throughthe valve and througha branch lineV VHill "to the :lower end of thelocater' pin of cylinder' 80,1-for'cing upwardly the-piston f rod8|.;andlowering thelocating pins`l11'and'1'8.

At this stage the Work piece is unclamped, the locating pins arewithdrawn and the transfer pins are raised in position to engage theirrespective workpieces.`

When the locating pins are lowered a limit switch is tripped energizingthe solenoid 99 and thus reversing the valve 96, pressure fluid Y'thenows through a pipe |4| and line |42 to the right hand side of thecylinder 35 forcing it to the left to advance the transfer bar and atthe same time forcing the uid from the left hand side of the cylinder 35reversely through the line ||4.V The check valve ||3 vprevents thepassage of the fluid directly to the line 2 and forces it through abranch line |43 and a speed controlling valve |44 to the valve andthence through the control valve 96 t0 an exhaust pipeY |45 leadingYtothe tank 90.

When the transfer bar 30 has completed its forward movement the cam |29will have reached the stem of the valve |3| depressing it and openingthe valve. The valve. |3| `now being opened and valve |30 being Closedpressure fluid flows from the line or pipe |00 through a branch line |46and thence through the valve 3| and delivery line |41 to the lower endof a control valve |48, opening this valve. Fluid then ilows from theline |00 through the valve |48 and through a line |49 to the upper endof the cylinder 80 thereby depressing this cylinder and lifting thelocating pins 21 when the piston rod 8| is lowered to raise the loweringpin 11.

Corresponding rotational'movement is transmitted to a cross-shaft |50which has gear teeth meshing with rack teeth on the piston rod. Fromthence the rotation of the shaft |50 is transmitted through a similarrack and pinion arrangement at the end of the shaft to a vertical rackbar immediately above a control valve |52 thereby lowering this valveand opening it.

As the valve |52 opens control pressure fluid is admitted from the line|49 through a branch line |53 and through the valve leading to a line|54 to a control valve |55, opening the latter; thereupon fluid flowsfrom the line |49 through valve |55 and a pressure control valve |56 -toa line |51 leading to the upper ends of the clamping piston 64 andthereby depressing this piston and lowering the vclamps to clampingposition. The transfer pins are also lowered at the same time.

It will be evident from this control, therefore, that the clampingplates cannot lower to clamping position until the locating pins are infully raised position. If there is any obstruction that would preventthe locating pins from rising and accurately locating the work pieces inposition, the clamping plates cannot lower to clamping position.

As the bushing plate clamps the valve |02 is opened and valve |03 isclosed tripping a limit switch which controls the movement of themachining mechanism, such as a drilling orboring machine or whatevermachine is at the par.- ticular station. o

The parts remain in this position until the machining operation iscompleted and the machining mechanism returns to its starting position.As the machining mechanism returns to its starting or back position ittrips a limit switch which will again de-energize solenoid 98 andenergize solenoid 91. When the loading station 22 of the next machine isempty and a new work piece is placed in the station I5 the vGyle 0foperation is repeated. I

Electric control The electric control for the solenoids 91 and 98 isshown diagrammatically in simplified form in Fig. 12 the positions ofcontrol switches being indicated dagrammatically in Fig. 1.

In this diagram-electric energy is supplied to a line |58 through asuitable start and stop switch mechanism and transmitted to the solenoid91 by a branch circuit which comprises in series an electric switch |59closed when a part is in the starting station 5; a switch |60 which isopen when the starting station 22 of the next machine is filled andclosed when it is empty; switches |6| and |62 which are closed when theclamping plates are lowered; a switch |63 which is open when thelocating pins are down and closed when they are up. Electric energy is,therefore, only supplied to energize the solenoid 91 and permit reversemovement of the transfer bar, when station 22 is empty, station I5 isfilled, locating pins are up and clamping plates are down in clampedposition. The opposite side of the solenoid 91 is connected through aline |65 to a return mainV Electric energy is supplied to the solenoid98 from the main |58, a switch |64 which is closed when the machiningmechanism associated with the particular transfer mechanism is inwithdrawn or back position and through a switch |61 which is closed whenthe mechanism of the succeeding machine is in withdrawn position, theopposite side of the solenoid 99 being connected through a branch |68 tothe line |65 and return main |66.

It will be obvious, therefore, that this soleno1d cannot be energized toadvance a work piece until the next machine is in position to receive awork piece. Any suitable start and stop mechanism may be employed tocontrol the supply of electric energy from a main |69 to the line |58.

As illustrated in Fig. 12 this may comprise a master stop switch |10 ina branch circuit I 1| having a shunt circuit |12 containing a startingswitch |13. The circuit |1| comprises an electromagnet |14 which closesa switch |15 from the shunt circuit |12 to the line |58 wheneverandwhile current passes through the line I1 When -both switches |10 and |13are closed current flows through therbranch line |12 energizing anelectro-magnet |16 to'close a relay switch |11 in a shunt circuit |10.This circuit leads through a control solenoid |19 which when energizedcloses a switch in the branch 1| As current ows through the twosolenoids |15'and |19 the switch |11 is closed and then the switch |80closes. When switch |80 is closed current flows continuously and at alltimes through the solenoid |19 maintaining a continuous closed circuit so long as the master stop switch |10 remains closed. When this circuithas once been established it remains whether the starting switch |13 isclosed or open. However, once the master stop switch |10 is opened thecircuit is not re-established upon releasing it but the starting switch|13 must again be closed. It will be understood, however, that this ismerely one way of establishing a starting and stopping control circuitand that other alternative systems may be employed. v

It may be noted also that the switches I5 and |62 may lbe doubleswitches tocontrol the starting of the machining mechanism upon thecompleting of the clamping operation.

In the above mechanism it will be observed that the transfer mechanismonce started will continue in operation as long as v work, pieces aresupplied to the'startingfposition or station I5,

'and that if this position should not besupplied the machine will stop,but be .in readiness Ytostart immediately upon placinga-fworl: piece inthe starting station.'

Notransfer will take place until the receiving position 22 of thenext'machine isi-empty and readyto receive a workpiece. Inthe event.that anygmachine should stopas, for-example, by the breaking -of adrill or toolor for any otherreason l.

and should; thereforeinotreturn .to its starting position, the transfermechanisms of an entire 'setor train will stop 'until this YdefectI iscorrected andr the respective machine returns to its original position.

It will be notednalsoV that no machining operation. canA start. until`thesclamping plates. are lowered to clamp` th'e vwork pieceiin positionand thatthis clampingv operation cannot take place until the .locatingpins have been .lifted to Ylocate beingv necessary that the delivery-endoff eachl mechanism as, for example, that from the station 2| ltothestation 22ifshould befsuch Ethat a work piece will slide fromithef railsof the .transfer mechanism to the rails of the next andthat itcomegwithin the widened'ends--of theguide -rails 24rand 250i asucceeding machine.

As fthe-f mechanism'.A of each :transfer 'machine operates independentlyof the mechanism of a Asucceedingmachine vany difficulties,y due to thefailure of any particular mach-ine, may be traced to that machine.

As the wiring and hydraulic systems areA relativelyv simple foreachimaohine anyfdiiicultyin anymachine may beieasily identiedi ortraced and corrected.4

Thefact that'- each transfer-machine is self maintained enables ittobe-readily adjustedf to changes iinv the assembly' line; For example;the positions of av drilling machine; or"boringma chine, or. other vtypeofmachineztooll maybe interchanged; additional transfer machines may beadded when it is desired to' accomplish 'additional machiningoperations, or they may-be subtracted from an assembly 'line when feweroperations-are to take place. Y

The-clamping. platesor bushings arefgenerally made with an open top so'that 'id-rilling or'boring operations may take place. vertically aslwell as horizontally.

Rswnil A cycle of operationof'a mechanism or a' train of mechanisms isas follows:

At the beginning-'of the operation the various machines willbe-running'as, for example, in a drilling machinethe drills will berotating and inV their withdrawn' or starting position, the clampingplates 5| and 52 will bein lowered position and through thefpush' rod|05 will open the valvev |02, Figs.v l and l0.' The transfer pins 40will also be1 loweredf by the elements 6| and 16 connected' to theclamping plates, Figs. 3 and 4, so that they may slide horizontallybelow the level of the supporting rails I 6 and l The locating pins 11and` |B will also bein locating position and through theA transmission"12 elements |50 and |5I,' Figs. 5'and 10, willA depress and'iopen thehydraulic valve |52." The transfer bar-or element 30 will be in itsforward position and through the transmission elements |5,|2'| willdepress and open the valve |3|.

If the load station 22 of the succeeding machine 231s empty Athe switch|60, Fig. 12, will be closed. The switches|6| and|62 are closed bytherlowering of the clamping plates, and the switch |63 Ais closed bythe locating pins in raised position,

and the switch |64 is closed by the machine 'elements, such as drills,etc., being in their withdrawn` or rearmost position.

If awork piece is now placed in the load station at |5zthe switch|59isclosedand aVV circuit completed through thesolenoid 91, whereuponfiuidipressure is admitted from the pipes 93' and 99 through the valve96 to the supply pipe III, Fig. l0,.and'thence to thevalve V| ill.`

The'valve |92' being opened uid also flows through the'line |0|, valve|02 and line |09`to the. lower p-art of Vvalve H0, .opening this valve.Fluidjthen `flows through the line |2, check valve ||3 and line ||4tothe left-hand. side of the cylinder: 35 causing the .transferelement30to moveto 'the ileft.

As Athe transfer bar moves 4to the left it rotates the transmissionmechanisms IIE-|21 to close valve |3| and open valve |30. Fluidthereupon ows from the pipe through the'line' |32 to the open valve |30and thence through the line |33 to the lower part of valve |34, openingthis valve, thereupon fluid ows through the pipe through the branch pipe|35', valve |34 and pipe V|36 to the lower parts of clamping` cylinders64,

pushing upwardly the piston 63, Figs. 5 and 6, and through thetransmission elements 60-66 raising the clamping plateY rodsV 53 and 54'and also raising the transfer pins to extend'above the supporting railsI6 and As the bushing plate rises .the valve |02 is released and closedand the valve |03 vis depressed andopened; thereupon pressure fluidflows from the pipe' |91 through the branch pipe |31 yand thenceVthrough the open valve |03 andv branch line |38 to the lower part ofvalve |39, opening this valve. Fluid then ows from-the pipe |35 throughthe opened valve |39 and branch pipe |40to the locating pin cylinder',causing the locating pins and 18 to be lowered through the transmissionmechanisms 8 I-BB. As the locating pins are lowered the-'movement ofthe'piston is transmitted through the' transmission elements |50 and|5I, Figs. 5 and 10, to depressand close the valve |52. At the same timethe switch |61, Fig. 12,is closed by the lowering of the locating pinand the solenoid energized.

Inasmuch as the switches |6| and |62 hav been opened by the lifting lofthe clamping plates, solenoid9`| will be de-energiZed-.the Vposition ofthe-valve V96-vvill, therefore, be. lreversed Aclosing the supply ofiuid to ,the pipe and opening it.. to the pipe. |03. Pressure fluid,therefore,

flows through the valve to the pipe |00 tothe right hand 'side of thetransfer barof cylinder 35. forcing this bar to the right andthetransfer pin in forward direction. The movement is retarded by theclosinggof the check valve ||3 shunting the return iluid throughthespeed control valve |44. The transfer element, therefore, movesforwardly'and as'the transfer pins l.are raised each work piece is;advanced from one station to the next.

As the transfer bar moves-forwardly the valve |30 is closed and at theend of the movement lthe valve |3| is opened Athusv returning` thesevalves to their initial position. Pressure fluid thereupon ows from thepipe through the branch line |46 and the opened valve |3| to the lowerpart of the control valve |48, raising and opening this valve. Pressurefluid thereupon flows from the pipe |00 through the Valve |48 to theupper end of cylinder 80 causing the locating pin to rise and depressingand opening valve |52.

Upon the opening of the valve |52 pressure uid flowing through valve |48and branch line |49 is admitted through and to the valve |52 and line|54 to the lower end of valve |55, opening this valve. Valve |48 stillbeing open, pressure fluid flows through the valve |55 and through apressure regulating Valve |56 and pipe |51 to the upper part of cylinder64, depressing the piston 63 and the clamping plates and clamping thepieces in position.

It will be apparent that pressure can only be admitted to the clampingplates as long as the valve |48 is opened, and accordingly, only whilethe locating pins are in raised position.

As the clamps are depressed they release and close valve |03 and depressand open valve |02 through the transmission mechanism above described.

The lowering of the clamping plates also serves to close the startingswitch of the machines, such as drilling machines, or boring machines,etc., so that these machines advance to perform a machining operation.As these machines complete their operation and return to startingposition the cycle repeats.

Having described the invention, what I claim is:

1. Transfer mechanism for moving a work piece in successive steps from aloading station to a work station of a machine and from said workstation to a receiving station which comprises a reciprocating transfermeans having means to engage a work piece at the loading station and awork piece at the work station, means to actuate said transfer meansforwardly a distance equal to the distance between said loading stationand said work station and reversely, locating means for engaging andpositioning said work piece at said work station, means for securingsaid work piece at said work station, means controlled by the loading ofa piece at said loading station and by the withdrawal of said posi- 14tion and securing means to actuate said transfer means forwardly andmeans positioned to be actuated by a work piece at said receivingstation to interrupt forward actuation of said transfer means.

2. Transfer mechanism for moving a work piece from a loading station toa work station and from a work station to a receiving station whichcomprises work piece supporting and guide rails extending from saidloading station to said work station and to a receiving station, areciprocating element extending longitudinally of said rails and movableforwardly and reversely a distance equal to the distance between saidstations, pins carried by and movable with said reciproeating elementand movable transversely into and out of position to engage a work pieceat each said work station and loading station, positioning means at saidwork station movable to engage a work piece and place it in position forwork, clamping means to secure said Work piece in position at said workstation, said clamping means being connected to and movable with, saidpins, uid operated means to move said reciprocating element forwardlyand an electric circuit to control the admission of fluid for theforward movement of said reciprocating element and having a switchpositioned to be actuated by a work piece in said loading station forthe admission of said fluid and a switch positioned to be actuated by awork piece at said receiving station to prevent the admission of saiduid.

HARRY F. PHILLIPS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,435,046 Birnstock Nov. 7, 19221,560,373 Birnstock Nov. 3, 1925 1,597,536 Murray Aug. 24, 19262,120,966 Clark June 21, 1938 2,160,476 Kampmeier May 30, 1939 2,193,840Oberhoffken et al. Mar. 19, 1940 2,238,921 Waldsmith Apr. 22, 19412,302,878 Muhl et al Nov. 24, 1942 2,438,999 Hartley et al. Apr. 6, 1948

